Oil compositions



as. at

penis-Wu Patented Dec. 8, 1953 Charles G. Towns, Beacon; N.Y.,;assig*nor to The 'l'ezxas' Company; New York, N. Y.. a; corporationof Delaware Nb Drawing. Apfilicatiofl August 25,1949, Serial No. 112,399

This invention relates to improvements in bydrocarbon oil compositions,and more particularly to the inhibition of foam and gas entrain-'- mentin such compositions" as are designed for use in special purpose oilssuch as are prepared for use in automatic transmission mechanisms andsome types of diesel engines.

While organo-silicon oxide condensation products, including bothsilicones and silicates; have been'indica-ted as foam inhibitors inlubricating oils, see Patent Nos. 2,416,563; and 2 ,416,504 toTrautmanet al. issued February 25; 947, they have not proven generallysatisfactory incertain applications, particularly where air or gasentrainment is a problem. Air or gas entrainment is to-be distinguishedfromso-called foam. Foam is the frothy oil and gas mixture formed on thesurface of oil. It is readily distinguishable from the oil proper, theseparation taking place at an oil-foam interface. Air or gas entrainmentis not readilydeterminable and involves an actual increase in the voiumeof the-oil because of the air or other gas entrained therein. Tests haveproven that the-remay be gas entrainment in the absence of foam;

In the past, theefiiciencies of such condensertion products have beendetermined by their-antiioam function. Relatively simpl-tes'ts'have beenused such as that wherein the oil to be tested is placed in a graduateand air, in the-forn'i of fine bubbles, is passed upwardly through thecolumn of oil at a opredetermined rate; The time given to form a givenamount of foam may be motor? or the amount of foam formed in a given maybe noted. Such a. test is disclosed the above-mentioned patents.

This test is apparently satisfactory for determining the foamingcharacteristics of certain types of oils for certain purposes but is notgenerally determinative of foaming for all types of oils and is notdeterminative of gas entrair'a merit.

For example, in the development of a special purpose oil for usehydraulic transmission mechanisms for automative vehicles such astheGeneral Motors Hydramatic; and Byriaflo'w transmissions and othertransmissions of tnejauto motive type, the oil aftertreatment with theusual liquid dimethyl siiicon'e polymer or 100 oentistokes at atemperature of 25 CL, was sat- 0 isfactory as regards foaming whentested by the CRC test, the latter being a test incorporating theprinciple of the test disclosed: the abovementioned patents but moreextensive as" regards temperatures as emfilaincd hereinafter.-'How'eyer;

gine, the oil foamed badly and was unsatisfactory.

, In both the above cases. gas entrainment as distinguished. fromfoaming was apparently resout to a large degree and appeared to be amaterial factor. Such gaser'rtrainn'ie'nt reduces the apparent specificgravity of the oil apparently in a somewhat spotty manner so that theresultant mixture is not uniform but is characterized by random gaspockets. The transmission mechanism or the pump handling the oil becomesnoisy and tends to vibrate. This is due, it is believed,

to the" different" resistances of the oil and: the oilgasmixture orpossible gas pockets alone to the mechanical mechanism. oil with i'ittieor no gas entrainment wilt ofier substantially uniform resistance to themechanical mechanismsb'ut an oil containing aconsiderable amount of gasdispersedat random oriri pockets will vary widely in resistance. Hence.the force opposing the pump or other mechanism willvary widely and giverise to the characteristic noise and vibration.. Without such gasentrainment the oitis substantially homogeneous and exerts a uniformforce against the' moving elements at the meohanisn'r.

The present invention has its principal object the solution of the foamand gas entraini-ne'nfi problems in such special applications ofhydrocarbon oils and the inhibition of foam and gas entrainment" in" themore general applicatiOIlS iff'a; more eflici'ent manner;

Another object" of the" invention is to provide hydrocarbonoilcompositions for bothgeneral and: special pur oses wherein thecharacteristics thereof, especially foaming and gas entrain ment,aregreatly improved.

A further object of the invention is the provision of novel hydrocarbonoils characterized by their operationm oi-l-handling mechanisms asubstantially quiet and vibration-free mamner.

Still another obie'ctof the: invention is the provision of a method fortreating hydrocarbon oil compositions whereby undesirable gasentrainment in operation is inhibited.

Briefly stated, the present invention is based on the discovery thatorgano-silicon oxide condensation products of relatively highviscosities are effective in inhibiting foam and gas entrainment inhydrocarbon oils wherein like materials of relatively low viscositiesare of little or no effect and are generally less efficient than thehigher viscosity materials. More specifically, the invention relates tospecial purpose hydrocarbon oil compositions having improved foam andgas entrainment characteristics, improvement being secured by the use oforgano-silicon oxide condensation products of relatively highviscosities. Such special purpose oils include hydraulic transmissionoils and special oils for lubrication of diesel engines.

The organo-silicon oxide condensation products or condensation productsof silanols or organo-silicols referred to herein are intended toinclude both silicones and silicates, preferably normally liquid, of thefollowing general compositions:

R n R[SiO]S iR (silicone) ts .tR

wherein R represents similar or dissimilar organic radicals such asalkyl, aryl, alkaryl, aralkyl and heterocyclic groups; the terminal Rsand ORs or other He and ORs may be substituted by hydroxyl groups; and nis one or more. Such compounds and their methods of preparation to formcompounds of different viscosities are well known to the art. Where R inthe foregoing formula is an aromatic hydrocarbon grouping,intra-substituents such as a halogen, a nitrogencontaining radical asN03 or NHz, a sulfurcontaining radical such as SOsH or SH, or aphosphorus-containing radical such as phosphite, phosphate or the thioderivatives thereof may occur.

Typical compounds include dimethyl silicone, methyl phenyl silicone,ethyl butyl silicone, methyl cyclohexyl silicone, dicyclohexyl silicone,diphenyl silicone, hydroxy phenyl methyl silicone, phenyl propylsilicone, phenyl isopropyl silicone, tolyl butyl silicone, tolyl amylsilicone, phenyl hydroxy ethyl silicone and the corresponding polymersof methyl orthosilicate and ethyl orthosilicate. Compounds containingsimple organic radicals such as methyl, ethyl and short chain alkylgroups are preferred. Suchcompounds may have hydroxyl groups or organicradicals as terminals.

The compounds are preferably incorporated in the composition to betreated by mixing them with a high boiling naphtha such as kerosine andmixing the resultant combination with the composition. For the purposeof the following description, it will be understood that sufficientkerosine is added to grams of the specific silicone or similar compoundto make up a total of 100 ml.

Before proceeding to a detailed description of the invention, thevarious tests used for determining the foaming characteristics ofhydrocarbon oils should be reviewed.

In the so-called CRC test, oil in a graduate is heated to 129" F. andcooled to 75:5" F.

In sequence 1, air at a rate of 0.2 cubic feet per hour is bubbledthrough the oil through a diffusion plate at the bottom of the graduate.The foam height is recorded at the end of a five minute period, thusgiving the zero minute reading. The air is shut off and the foam isrecorded again at the end of a ten minute period, thus giving the tenminute reading. In sequence 2, the same steps are followed except thatthe temperature is raised to 200i5 F. In sequence 3, the same steps arerepeated with the temperature returned to 75i5 F.

In the Carnegie foam test which has been developed primarily for thetesting of oils used in hydraulic transmission mechanisms and the like,the oil being tested passes through a pump having a submerged intake andan air-open discharge above the body of oil. Simultaneously twopropellers are used to agitate the oil body. The oil is heated to atemperature of about 200 F.

After the oil is brought to temperature, the propeller motor is turnedon and the pump discharge pressure set at lbs. per square inch. Afterone minute, the motor is shut 01f and the height of foam, i. e., thedistance from the top of the foam to the oil-foam interface, ismeasured. The foam collapse time is taken as the time elapsing betweenthe stopping of the motor and the first appearances of the oil surfacethrough the foam. The foam height is reported to A," and the foamcollapse time to one second. Approximately six quarts of oil arerequired for the test.

The VVL test is based on a proposed Federal specification of October l,1941, for universal gear lubricants. It involves the churning of thelubricant in a Mixmaster or its equivalent having a pan '7" in diameterand 3%," deep, the pan being supported on the turn-table mounted in thecenter bearing hole of the two bearing holes in the Mixmaster baseplate. 500 ml. of the lubricant is churned with concave paddles at roomtemperature for 15 minutes at a beater speed of 550 R. P. M. After thechurning period, the lubricant is allowed to stand one hour. The foam ismeasured at zero minutes and at ten minute intervals through one hour.

In the Towne foam test, a Mixmaster or the equivalent is used incombination with a 500 ml. graduate cylinder. 400 grams of the sampleisheated to 150 F. and maintained at that temperature for 30 minutes. Itis then allowed to cool to room temperature by standing for asufficiently long period. 200 grams of the test oil is weighed into an800 ml. beaker and placed in a constant temperature bath at the testtemperature of 75 F. After reaching temperature, the oil is stirred forexactly three minutes. The contents of the beaker are then pouredquickly into a 500 ml. graduate cylinder and the graduate placed in thetemperature bath. The volume of foam is determined at 0, 10, 20, 30, 40,and minutes starting with zero time as four minutes after the stirringoperation is begun. In this test, the oils of SAE 10, 20 and 30 gradesare tested at F. and oils of SAE 40, 50 and 60 grades are tested at F.

In all the foregoing tests, the objective has been to measure the foamand no attention has been paid to gas entrainment. Apparently gasentrainment and its possible effect in use of the oil has been entirelyoverlooked.

As an example of a practical application of the invention, a hydraulictransmission fluid was prepared with a mineral oil base. About 3.5 to

4.5% of an additive off the inethacrylatepolymer type, about 2.5 to 3.5%of anadditive of the sul furized sperm oil type-and'about 0.8to 1.0% ofan additive of a bariumthiophosphate-sodium sulfonate type in a lightoil as acarrier, all by weight, were added to a base. compound formed ofa refined paraffin vbaseoil having .a'

viscosity SSU at 100F. of aboutlni).

The methacrylate polymer type additive contains approximately 40% ofv apolymerized ester of methacrylic acid having a :rnolecular I weightbetween 10,000 and 15,000 and or the following general formula:

H CH5 wherein R. is a mixture of alkyl groups) havin from}; to .16carbon atoms such as cetyl, lauryl and octyl groups. The additive isformed by dissolving the polymer in a Mid-Continent solvent-refined 150neutral oil. The result is a clear, light-amber colored viscous. fluidhaving a -Sp. Gr. 60/60 F. of 0.89-0.90, and. flash point diluted to 10%solids with a S, A. E. 20 oil. COC, of 405 min, a viscosity; Kinematicat 210 F., es. of 600-800 and a Neut. No. of 0.4 max.

This additivehas been found valuable as a viscosity index improver and apour point depressant.

The sulfurized sperm oil type additive can be described as having asulfurized sperm oil and lanolin base, theprincipal constituent being asulfurized derivative of cetyl oleate:

n-C mHasO-C -4 GH2):-l]CH -GH3=(CH2)1(LH It is probable that the sulfurenters the molecule at the double bond to form a ring structure somewhatas follows:

-CH--CH R0 s on .no SBa-S on wherein R=C7+Ca+C1o alcohols. The additiveis a dark oilyliquid of a density of about 1.016. It contains about 6.0to 7.3% barium, about 2.6 to 3.2% phosphorus, about 6.0 to 7.9% sulfur,and-about 0.25 to 0.40% sodium all'by weight. Its principal function isas an antioxidant.

With the addition of 225 parts per million of 100 cs. silicone (dimethylsilicone polymers) in kerosine (about22.5 p. p. m. silicone) to theabove-described hydraulic transmission fluid, a Carnegie; foam test ofthe fluid showed a foam height oil?" and a foam collapse time of 42seconds. When only 100 p. p. m. of the same silicone but of 1,000 cs. inkerosi-ne (about 10p. p. m. silicone) was used, the foam height was lessthan k" and the foam collapse time was zero, that is,'there was nosustained foam. The use of thehigher viscosity silicone also appeared tosubstantially inhibit gas entrainment since the oil so treated when usedin a transmission enabled quiet and smooth operation in contrast to thenoisy operation when oil treated with the silicone of 100 cs. was used.This particular fluid had a viscosity SSU at 100 F. of 204.4 and at 210F. :of 52.3. It had .a viscosity index of about 140.

A comparison of the 22.5 p. p. m. 10.0 cs. silicone givinga foamheightof /2" and the .10

p. ppm. 1,000 cs. silicone giving a foam height of. less than 34;"establishes the 1,000 cs. silicone asxbeing far more efficient than asilicone of the same composition but of lower viscosity. In brief, the1,000 cs. material when used in an amount less than of the 100 cs.material was four times as effective in inhibiting foam.

On afurther test. of this same fluid at ten peratures ranging from 200to 275 F. with silicone (1,000 cs). contents of 10-15 p. p. m., thefoam-height was A or less and the foam collapse time except at extremelyhigh temperatures was zero. At the high temperature of 275 F., the foamrequired only 23 seconds for collapse.

This particularfluid is a particularly good hydraulic transmission fluidin that it is capable of transmitting power efiiciency through eitherthe fluidcoupling or torque converter, it is an efficient lubricant forthe complicated and precisely machined moving parts such as the variouspump units involved-and is capable of satisfactorily lubricating andpreventing wear on any gearing contained in the transmission unit. Ithas the correct viscosity .and a pour point of at least -35 F. whichsatisfies the requirements of temperature extremes liable to beencountered. It is stable in service, resistant to oxidation and depositformation, and resistant to foam formation and gas entrainment whichcould interfere with the efliciency of the power transmission.

Strange to say, the increased efficiency'of the higher viscositysilicone in this particular fluid is not indicated .by the CR0 orsimilar tests that determine only foam presumably because such tests donot simulate the actual operation in a hydraulic transmission and do notdetermine gas entrainment.

Respecting this particular hydraulic transmission fluid, it has beenfound that regardless of the amount of 100 cs. silicone employed, thefoam as determined by the Carnegie foam test cannot be reducedsufficiently to pass specifications. on

. the other hand, the use of silicones of higher viscosities has solvedthe foam problem.

In another instance, a special lubricating oil wasprepared for use indiesel engines by combining a base. oil (having a gravity, API of22.5-28.5, flash, 0. O. C. min. 420 F., fire, C. O. 0, min. 470viscosity, S. S. U. at F. of 540-530, viscosity index 76 min, pour point5 F. max.) with about 16.5% by volume of an additive classified as abasic barium sulfonate, barium amount of the same silicone of 1,000 cs.was used, the foam at minutes was only 150 ml., a reduction of about52%. With 5 p. p. m. of the silicone of 100 cs. 300 ml. foam wasobtained in 5 minutes. An equivalent amount of 1,000 cs. silicone of thesame composition reduced the foam at 5 minutes to 50 ml., a reduction ofabout 33 With p. p. In. of the 100 cs. silicone, 250 ml. foam wasproduced in 5 minutes. With an equivalent amount of 1,000 cs. silicone,only 30 ml. foam was formed at 5 minutes, a reduction of about 88%. Evenwith 100 p. p. m. of the 100 cs. material, '70 ml. foam was formed in 5minutes.

In connection with the relation of gas entrainment, its ill-effects andits determination, tests were run with a straight naphthene base oilhaving a gravity API of 18.0 to 21.0, flash, COC F. min., 3'70, fire,COC F. min, 420, viscosity, S. S. U. at 100 I. of 550-580, viscosity S.S. U. at 210 F. of 53-56 neutralization number of 0.1 max., and with noadditives of any type contained therein. In this case, both in actualoperation and in laboratory tests, the higher viscosity organo-siliconcompounds were found effective as regards the inhibition of both foamingand gas entrainment whereas the lower viscosity compounds were found tobe of little or no effect. This particular oil is of special value inthe lubrication of large diesel engines such as those of Nordbergmanufacture (model TS-Z cycle).

In one specific instance, the installation included six Nordberg 2-cyclediesel engines of 7325 horsepower rating each with generators di rectlyconnected thereto. In this installation each engine had a gear traincomprising four large gears with an oil spray at each gear meshing. Whenoperating with straight oil, there was a great deal of rattling andvibration in the circulating pumps for this oil, apparently due to air(or fixed gas) entrained in the oil by the aforesaid gear trains.

With the addition of a dimethyl silicone of 100 es. in an amountequivalent to about 3 p. p. m., there was no noticeable change in thenoise or vibration of t is pumps. With the use of about 3 to 4 p. p. m.of the same silicone but of 1,000 cs.,

there was immediate and substantially permanent improvement in that thenoise and vibration were substantially eliminated.

To check the effect of the higher viscosity sili- A cones, the operationof the engine insofar as the oil is concerned was simulated in thelaboratory by the use of a circulating unit formed. of standard pipe andfittings where the oil was circulated by a Chevrolet automobile waterpump driven by i,

a H. P. motor at a speed of about 2100 R. P. M. Air was added to thesystem at the suction side of the pump and the circulating oil heated bya thermostatically-controlled electric heater. In

this way, the actual conditions in the engine as n to the entrainment ofair and temperature were simulated. The unit was charged with 5000 cc.oil and the oil circulated at 130 F. with -60 cc./min. of air beingadded to the suction side of the pump. Both the foam height and increasevolume increase of the oil was reduced to about 8%. Foam was stillformed.

With a fresh charge of oil, a dimethyl silicone of 1,000 cs. was used inamounts of 5, 10, 50 and 100 p. p. m. The 5 and 10 p. p. m. additionswere found to reduce the volume increase of the oil and the 50 p. p. 'm.addition substantially eliminated all volume increase. Increased amountsof silicone did not have any adverse effect. This particular test wascontinued for more than two days during which time there was no changein the volume of oil.

Another run was made with the same silicone but of 100,000 cs. in aconcentration of about 5 p. p. m., the silicone being dissolved ordispersed in ethyltriethyloxy silane. With a concentration of 5 p. p.in. corresponding to about 40 p. p. m. of the silane, there was somereduction in air entrainment or volume increase. With a second 5 p. p.m. addition, making a total of 10 p. p. m., the air entrainment wasreduced to substantially zero. The silicone was effective over the threedays of the test.

The apparatus was thoroughly cleaned between each test.

It should be added that silicones of 500 cs. were tried in the same oilwith the more conventional foam tests. About 7% foam was produced andspecial measurements of the increase in volume of the oil showed anincrease of about 7%.

Summarizing this experience, it will be noted that with this oil havinga tendency to increase in volume up to 13%, the silicones of 100 cs. and500 cs. were substantially inefiective whereas silicones of 1,000 cs.and 100,000 cs. were substantially and completely effective. Theseresults are particularly significant since they demonstrate the value ofthe simulated engine test in determining both foam and gas entrainmentand illustrate the efficiency of the higher viscosity silicones in astraight oil in which there are no oil improving additives or agents ofany type and in which foaming and gas entrainment are problems.

Equivalent increased efficiencies of organosilicon compounds of higherviscosities have been demonstrated in tests with other types ofhydrocarbon oils.

In test on a typical base oil, dimethyl silicones of low viscositiessuch as 6.2 cp. (about 6.4 cs.) and 85 op. (about 87 cs.) were found inthe CRC foam test, sequence 1, to hold the foam down to 10 ml. after 5minutes whereas dimethyl silicone of 884 op. (about 910 es.) in the sameproportion was found to prevent any foaming whatsoever.

In the case of an industrial gear lubricant having a viscosity SSU at100 F. of 2250-2450, the base lubricant when tested as to foam characteristics by the VVL foam test, gave 500 ml. foam at the 0, 15, 30 andminute intervals and 450 ml. at the 60 minute interval.

With the addition of 5 p. p. m. of dimethyl silicone of 1,000 es, thefoam at zero minutes was only m1. and the foam at the remainingintervals was only 25 ml. When 1.4 p. p. m. of dimethyl silicone of250,000 cs. was used, 50 ml. of foam was obtained at the zero and 15minute intervals, 25 ml. at the 30 minute intervals, and only traces offoam at the 45 and minute intervals.

The results of such tests indicate even greater effectiveness of theorganic-silicon compounds of higher viscosities.

In the case of a refrigerator oil having a viscosity SSU at F. of300-324 and containing and ml. in 10 minutes. The addition of 2.5

p. p. m. dimethyl silicone of 1,000 es. reduced the 0 minute foam-tomml.,a reduction ofabout 97% and the '10 minute foamto 0, a reduction of100%. The same results were obtained with the use of only 1.4 p. p .-m.orapproximately;one half as muchdimethyl silicone of 50,000 cs; 4

With :a rock drill lubricant having a viscosity SSU at 100 F. of550-610, tested-by the CRC foam test, sequence 1, the foam at Ominuteswas 540 ml. and. the foam at, 10 minutes was 440 ml. In .sequenceg2, thefoam at 0 minute was 160ml.- and at 10 minuteswas 0. In sequence- 3, thefoamxatzO minutes was 690ml. and at 10 minutes was 620 m1.Theaddition-of 1p.- p.- m-.- of ;di-,- methyl silicone of 100 cs. showedvery little improvement as respects sequences 1 and-2 the foam at 0minutesinsequence 3 being; reduced to .100 ml.

The use of an equivalent amountof dimethylsilicone of 1,000 cs. reducedthe foam in sequence 1 to 30 ml. at 0 minutes, a reduction of 94% and to0 at 10 minutes, a reduction of 100%. In sequence 2, the foam at 0minutes was 80 ml., a reduction of 5% and 0 at minutes, a reduction of100%. In sequence 3, the foam at 0 minutes was ml.,. a reduction of 97%and at 10 minutes was 0, a reduction of 100%. Substantially the sameresults were obtained by the use of only 0.8 p. p. m.,of.a silicone of10,000 cs., with 0.5 p. p. m. of a silicone of 50,000 cs., with 0.4 p.p. m. of a silicone of 100,000 cs.,.and with 0.3 p. p. m.- of a siliconeof. 250,000 cs.

' In a Carnegie foam testonanioil formed from a baseoil and an additiveor the methacrylate polymer type and having a viscosity SSE" at 100 F.of about 198, the oil with '7 p. p. m. dimethyl silicone of 100 cs. hada foam height of 1%" and a foam collapse time of 39 seconds. Whentreated with only 5 p. p. m. of the same type silicone of 1,000 cs., thefoamheight was less than and the foam collapse of the order of:

2.5 seconds.

The same oil treated with 10 p. p. in. basin-y cone of 100 cs. showed afoam height of A and a foam collapse time of 39 seconds. Whentreatedwith 10 p. p. m. of alike silicone of 1 ,000 c s;, the

foam height was less than and the foam c01- lapse time was 0, i. e.,there was no continuous layer of foam.

The same base oil treated with 80 p. p. m. of 100 cs. silicone had afoam height of /3" and a foam collapse time of 20 seconds, thus,indicating the improved anti-foam efficiency of the higher viscosityorgano-silicon compound.

The improved results in inhibition of foam and gas entrainment obtainedby the higher viscosity organo-silicon compounds is evidenced by theirproven greater efficiency even when used in smaller quantities and theirability to inhibit foam and gas entrainment in some instances where thelow viscosity materials are substantially ineffective. This isparticularly true in uses such as in hydraulic transmissions and in somepumps wherein the oil is subjected to turbulence in the presence of airor some other gas.

From the data obtained .thus far, the effective higher viscosityorgano-silicon compounds range from viscosities SSU C. of about 900 cs.to 250,000 es, and there is reason to conclude that the compounds areincreasingly effective in proportion to their viscosities.

v 1. -:W1.1i1e1t e: .t .r1 nection with hydrocarbon oil compositions, itis to be understood that it is also applicable to other organic liquidsand mixtures, containing the same.

Obviously many modifications and variations of the invention as aboveset forth may be made without departing from .the spirit and scopethereof, and, therefore, only such limitations should. be imposed as areindicated in the appended claims. Q

I-claim: V

1. A substantially non-foaming and non-gas entraining-composition ofmatter comprising a major portion-of a liquid hydrocarbon oil and aminor proportion of an additive and a liquid dihydrocarbon siliconepolymer of a minimum viscosity of about 900 cs.

2. A power transmittin fluid for use in hydraulic transmissions and thelike comprising hydrocarbon-oil; an additive containing a moththiophosphate-sodium sulfonate type, and sufi'icient of a liquiddihydrocarbon silicone of a minimum viscosity of about 900 cs. toinhibit foaming and gas entrainment thereof in operation.

3. A power transmitting fluid for use in hydraulic transmissions and thelike comprising hydrocarbon oil, about 3.5 to 4.5% of an additive.

containing a methacrylate polymer having a molecular Weight of between10,000 and 15,000,

about 2.5 to 3.5% of an additive of the sulfurized sperm oil type, about0.8 to 1.0% of an additive of about 900 cs.-to inhibit foaming and gasentrainment thereof in operation.

4. A-power transmitting fluid for use in hydraulic transmissions and thelike consisting essentially of hydrocarbon oil, about 3.5 to 4.5% byweight of an additive consisting essentially of about 40% by weight of apolymerized ester of methacrylic acid having a molecular weight between10,000 and 15,000 and of the following general formula:

pac s:

0 l o I 0 ii wherein Ris a mixture of alkyl groups having from to 16carbon atoms, about 2.5 to 3.5% by weight of an additive comprisinglanolin and a sulfurized derivative of cetyl oleate, about 0.8 to 1.0%by weight of an additive comprising sodium sulfonate and a bariumcompound of the following general formula:

has been described in con-- 11 methacrylic acid having a molecularweight between 10,000 and 15,000 and of the following general formula:

wherein R is a mixture of cetyl, lauryl and octyl groups, about 2.5 to3.5% by weight of an additive comprising lanolin and a sulfurizedderivative of cetyl oleate, about 0.8 to 1.0% by weight of an additivecomprising about 12% by weight sodium sulfonate and about 42.5% byweight of a barium compound of the following general formula:

R0 s s 03 P P \RO/ $BaS \OR wherein R=C7+C8+C10 alcohols, and suflicientof a liquid dimethyl silicone of a minimum viscosity of about 900 cs. toinhibit foaming and gas entrainment by the fluid in operation.

6. A power transmitting fluid for use in hydraulic transmissions and thelike comprising a refined paraffin base hydrocarbon oil having aviscosity of about 100 SSU at 100 F., about 3.5 to 4.5 by Weight of anadditive comprising about 40% by weight of a polymerized ester ofmethacrylic acid having a molecular weight between 10,000 and 15,000 andof the following general formula:

wherein R is a mixture of cetyl, lauryl and octyl groups, about 2.5 to3.5% by weight of an additive comprising lanolin and a sulfurizedderivative of cetyl oleate, about 0.8% to 1.0% by weight of an additivecomprising about 12% by Weight sodium sulfonate and about 42.5% byweight of a barium compound of the following general formula:

R0 s s 0R P 1 110 s s OR 12 wherein R=C7+Cs+C1n alcohols, and'sufiicientof a liquid dimethyl silicone of a viscosity of about 1,000 cs. toinhibitfoaming and gas entrainmentby the fluid in operation.

7. A composition of matter consisting essen-- tially of a liquidhydrocarbon and an additive, and sufficient of a liquid dimethylsilicone polymer of a viscosity of about 1,000 cs. to inhibit foamingand gas entrainment.

8. A lubricating composition adapted. for use as a diesel lubricant withfuels of relatively high sulfur content comprising a liquid hydrocarbonand a substantial proportion of an additive consisting essentially ofbasic barium sulfonate, barium dithiophosphate and a sulfurized terpene,and sufficient of a liquid dihydrocarbon silicone of a minimum viscosityof about 000 cs. to inhibit foaming and gas entrainment in operation.

9. A lubricating composition adapted for use as a diesel lubricant withfuels, of relatively high sulfur content comprising a hydrocarbon oilhaving a C. O. C. flash point of about 420 and a viscosity of 5404530SSU at about 10.5% of an additive consisting essentially of basic bariumsulfonate, barium dithiophosphate and a sulfurized terpene, andsufficient of a liquid dihydrocarbon silicone of a viscosity of about1,000 cs. to inhibit foaming and gas entrainment in operation.

CHARLES C. 'rownn.

References Cited in the file of this patent UNITED STATES PATENTS OTHERREFERENCES Kauppi et al., Organo-Silicon Compounds for InsulatingElectrical Machines, Reprinted from Transactions of the AmericanInstitute of Electrical Engineers, N. Y. (3., N. Y., vol. 64, 1945, 4pages.

Kauppi et al., Silicone Fluids in Hydraulics and Lubrication, Reprintedfrom Product Enginering, February 1949, 5 pages.

1. A SUBSTANTIALLY NON-FOAMING AND NON-GAS ENTRAINING COMPOSITION OFMATTER COMPRISING A MAJOR PORTION OF A LIQUID HYDROCARBON OIL AND AMINOR PROPORTION OF AN ADDDITIVE AND A LIQUID DIHYDROCARBON SILICONEPOLYMER OF A MINIMUM VISCOSITY OF ABOUT 900 CS.